1. Field of Invention
This invention relates generally to maintenance and repair devices used to test, service, and replace switched electrical lighting, and other electrical devices, that are controlled by modular photoelectric control switches.
2. Description of Prior Art
Modular photoelectric control switches, commonly called photoelectric cells, are used to control a wide variety of electrical devices. The most commom devices are lights, which are sometimes referred to as dusk-til-dawn lights, such as street lights and advertising sign lights. Most any other electrical device which is desired to be switched on, or off, at the advent of night or day may utilize modular photoelectric control switches. For examples, security sensors and heating and airconditioning units may also be switched. Modular photoelectric control switches will automatically switch in correlation to a design threshold of the switch and the amount of light striking its photoelectric sensor.
Most modular photoelectric control switches are located overhead, above human reach. This reduces interference with the amount of light striking the sensor. When it is known or suspected that modular photoelectric control switch has malfunctioned, a repairman must elevate to the switch location to identify the problem and take corrective action. Currently the module is serviced by elevating the repairman by means of manual climbing, the use of hydraulic lifts, and climbing with the assistance of ladders, or other climbing equipment. The use of such elevating means, to access the module by hand, is either costly or timely inefficient, or both, and is often unsafe. A means for repairmen to safely and efficiently test and repair overhead modular photoelectric control switches, from ground level, is needed.
That need is met by this invention, herein called, the modular photoelectric control installation device. By attaching this device to a standard telescopic pole, alternatively referred to as a long pole, a repairman can perform all normally required test and maintenance of modular photoelectric control switches, from ground level. Telescopic poles are associated with a variety of overhead electrical maintenance tasks, by use of various attached devices. Such specialized attachments may provide a means to replace fuses, cut cables, replace cotter keys, install electrical insulators, disconnect hot lines, and dispense from aerosol cans. Another attachment removes the bases of broken bulbs. Some of the most common long pole attachments are especially made to replace defective overhead lightbulbs. There are several types of bulb changers available commercially. One is commonly called the McGill lamp changer. It should be noted here, that one embodiment of the current invention can also change bulbs.
But, there has not been available a reliable, efficient, and safe means of testing and replacing the modular photoelectric switches. Yet, most switches are connected to, and usually located close to, a lightbulb. Usually, the bulb is a high intensity sodium, or mercury vapor bulb, when used in conjunction with a modular photoelectric control switch. Most commonly the switch and bulb are co-located in the same fixture, such as in a street light. Unless there is physical damage to either the bulb or the module, it is not normally possible to visually determine which component has malfunctioned. Basically, the same is true when the module is used with nonlight emitting components, because most repairs are made during the daylight hours. Therefore, electric current in the module would normally be switched off. Simply put, the appearence of both components will often be the same, even if both the bulb and the module were otherwise known to be defective.
In unknown situations, most repairmen simply proceed with a trial-and-error solution by replacing the bulb by means of a long pole attachment. If the problem subsequently proves, by deduction, to be located in the module the repairman will return and somehow gain hand access to the module. There exist a long pole attachment which will test the module. It is basically an opaque bonnet, which is lowered over the sensor of the module. Thereby, the light level is lowered and causes the module to switch. However, this attachment is not widely used. Unless both components function when the bonnet is used, it has no further utility in identifying and correcting the malfunction.
The modular photoelectric control installation device, however, performs the same test functions as the bonnet device. Furthermore, as necessary, it can subsequently remove and replace the module. Most new modular photoelectric control devices are designed to briefly self-test, regardless of light levels, by switching when initially installed. At this point in the test and repair process, by using the current invention, the repairman can deductively conclude which, if any, components are still defective. Yet, the repairmam has not been forced to use an extended trial-and-error repair method. Nor has it been necessary to expend the time, expense, and risk of working above ground level.
An assortment of hand tools have been adapted for use with the telescopic poles and are interchanged via a universal head. Such tools include hammers, screwdrivers, socket wrenches, and saws. These tools are used, within practical limitations, to make overhead electrical repairs. They are manipulated with the telescopic poles, basically as an extension of the hand and arm. Specialized interchaneable devices have also been adapted for overhead work with the telescopic pole. Some examples include insulator clamps and fuse pullers. These function mechanically when the repairman twist the pole with wrist action. Both hand tools and specialized devices have also been devised, that are activated by cables running the length of the telescopic pole.
Pulling the cable might depress a lever to activate an aerosol can button, or activate the release lever on vice grip pliers. Cable activatation, however, increases demands on manual dexterity and complicate the device. Even given the vast variety of tools and specialized devices adapted to pole use, none can safely, reliably, and efficiently complete the tasks testing and replacing modular photoelectric control switches. None prior to the current invention. The major reasons for the prior situation are largely related to both the design and construction of the photoelectric control switches.
Modular photoelectric control switches can vary somewhat in size and shape. However, most are approximately the size of a small apple. Most have either a basically cylindrical or truncated conical shape. The current invention adjusts to all known shapes and sizes. Nearly all control switches are encased with hard plastic, and similar materials, with smooth surfaces. The surfaces tend to create slippage of gripping members. If additional pressure is applied to the relatively small surface area, to overcome slippage, the case might become damaged. The sensor portion of the case is the most susceptible to damage by either excessive pressure or slippage. Slight damage to the case may merely reduce the effectiveness of control switch. More severe damage can produce an electrical shock hazard to a repairman.
Near all modular photoelectric control switches are slightly flared around the circumference of the base. The flare serves as a weather collar, when seated into the standardized power recepticle. As a module, photoelectrical switches must be plugged into the standardized power recepticle and twisted to lock them in position. This is accomplished by inserting the standardized three-pronged electrical contacts, located in the base of the control switch, into recepticle and twisting it approximately thirty degrees. Often the contacts become corroded, fused, or bent. These situations increase the amount of force needed to remove and install the module. Since the required force is exerted on the case of the photoelectric switch, it is critical that applied force not damage the case. The current invention dissipates pressure over a large portion of the case surface and, therefore, negates slippage between itself and the case.
Another difficulty overcome by the current invention is that of keeping the control switch case gripped, when it is lowered to groung level, or raised up. At times the distance exceeds thirty feet. But, inherent in the mechanical functioning of the current invention is its ability to maintain a constant pressure with a gripping member. Maintaining positive control during removal, will greatly assist positioning a control switch during installation. Additionally, embodiment of many pole adapted devices restrict the locations from which a repairman may perform an associated task. Some rejected embodiments, as related to the current invention, had similar disadvantages. However, the final embodiment of the current invention has no such restriction. The current invention is omnidirectional, imposing no location restrictions on the repairman. In arriving at a final, and functional, embodiment of the current invention, many existing gripping-type devices and principles were discarded as unusable. Included were devices incorporating box end ratchets, stud extractors, basin wrenches, slip and locknut wrenches, screw-type flare tools, pipe and other types of adjustable wrenches. As well as, screw-type clamps, including pipe cutters and gear pullers. Piston ring compression sleeves were also rejected as unsuitable. A suitable device has a near equal capability to act upon the control switch in opposing directions, without slippage. That is, to push and pull, to lift and to lower, and to twist right and left. Hence, the embodiment of the current invention.
Finally, the current invention can be remotely disconnected from the the telescopic long pole whenever desired, or when required by emergency situations. This capability is not found in other specialized devices associated with telescopic long poles. Rather, it is a unique safety feature of the current invention.